In recent years, research and development on light emitting diodes (LEDs) of blue and green made of nitride semiconductor such as GaN have been promoted. In the research and development of an LED, improvement in light extraction efficiency is a major issue.
For example, a semiconductor light-emitting device directed to improve light extraction efficiency by forming unevenness or roughness on the surface of a metal layer provided on a backside side of a permeable substrate is proposed. And for another example, a semiconductor light-emitting device directed to improve the light extraction efficiency by forming unevenness on a backside of a permeable substrate is also proposed.